Heat dissipation device and heat dissipation fins thereof

ABSTRACT

A heat dissipation device for being in thermal contact with a heat source includes multiple heat dissipation fins, a heat pipe and a fan. Each of the heat dissipation fins includes a plate and an air guiding body. The plate has a thermal contact side used for being in thermal contact with the heat source. An acute angle is formed between an extension side of the air guiding body and the thermal contact side. The heat pipe penetrates through the plates. The fan used for forming an air current is installed at a side of the heat dissipation fin opposite to the thermal contact side. The air guiding body and the heat pipe are disposed in a flowing path of the air current. Thereby, the air current is guided toward the heat pipe and the amount of air flowing through the heat pipe is increased.

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No(s) 201210442383.9. filed in China, P.R.C. onNov. 1, 2012, the entire contents of which are hereby incorporated byreference.

TECHNICAL FIELD

The disclosure relates to a heat dissipation device, and moreparticularly to a fan structure and its blades.

BACKGROUND

As the technology in electronic field evolves, the efficiency ofelectronic components improves. However, the enhancement on theefficiency of electronic components causes the amount of heat producedto increase. The heat keeps accumulating in the electronic componentsand causes the temperatures of the electronic components to increase.The electronic components may crash or even burn up when the heat maynot be removed effectively from the electronic components to lower thetemperatures. Therefore, instead of working on enhancing the efficiencyof electronic components, the problem the electronic industry faces ishow to remove the heat generated from electronic components effectively.

Generally speaking, water-cooled heat dissipation device and air-cooledheat dissipation device are used to remove the heat produced byelectronic components in the industry. The heat dissipation principle ofwater-cooled heat dissipation device refers to using air compressor orpump to drive the cooling fluid in the cooling pipe to exchange heatwith the electronic components. Thereby, the heat of the electroniccomponents may be removed. The heat dissipation principle of air-cooledheat dissipation device refers to using fan to guide cold air to flowthrough the electronic components in order to exchange heat and toremove the heat of the electronic components. Comparing to thewater-cooled type, the air-cooled heat dissipation device is morecost-effective because air compressor, pump and cooling fluid are notrequired. Therefore, the air-cooled heat dissipation device is widelyused in the industry to remove the heat of electronic components.

However, the conventional air-cooled heat dissipation device stillcannot effectively remove the heat produced by high-end electroniccomponents in the market. Therefore, considering cost-effectiveness andheat dissipation effect, it is highly demanded to develop air-cooledheat dissipation device with higher heat dissipation effect.

SUMMARY

An embodiment of the disclosure provides a heat dissipation deviceconfigured for being in thermal contact with a heat source. The heatdissipation device comprises a plurality of heat dissipation fins, aheat pipe and a fan. Each of the heat dissipation fins comprises a plateand an air guiding body. The plate has a thermal contact side configuredfor being in thermal contact with the heat source. The air guiding bodyis protruded from the plate. An acute angle is formed between anextension side of the air guiding body and the thermal contact side. Theheat pipe penetrates through the plates and is kept away from the airguiding body at a distance. The fan is installed at a side of the heatdissipation fin opposite to the thermal contact side. The fan isconfigured for forming an air current. The air guiding body and the heatpipe are disposed in a flowing path of the air current. Thereby, the aircurrent is guided toward the heat pipe and the amount of air flowingthrough the heat pipe is increased.

Another embodiment of the disclosure provides a heat dissipation finsconfigured for installing a fan and a heat pipe. The fan produces an aircurrent. The heat dissipation fin comprises a plate and an air guidingbody. The plate has a through hole for accommodating the heat pipe. Theheat pipe is in thermal contact with the plate. The plate has an airoutlet side. The air guiding body is protruded from the plate. The airguiding body is disposed in a flowing path of the air current, and anacute angle is formed between an extension side of the air guiding bodyand the thermal contact side. Thereby, the air current is guided towardthe heat pipe and the amount of air flowing through the heat pipe isincreased.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details. In other instances, well-known structures and devicesare schematically shown in order to simplify the drawing.

FIG. 1 is a perspective view of a heat dissipation device according toan embodiment of the disclosure;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3A is a plan view of a part of a heat dissipation fin in FIG. 1;

FIG. 3B is a plan view of a part of the heat dissipation fin accordingto another embodiment of the disclosure; and

FIG. 4 is an illustration of an air current of the heat dissipationdevice in FIG. 1.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details. In other instances, well-known structures and devicesare schematically shown in order to simplify the drawing.

Please refer to FIGS. 1 to 3B. FIG. 1 is a perspective view of a heatdissipation device according to an embodiment of the disclosure. FIG. 2is an exploded view of FIG. 1. FIG. 3A is a plan view of a part of aheat dissipation fin in FIG. 1. FIG. 3B is a plan view of a part of theheat dissipation fin according to another embodiment of the disclosure.A heat dissipation device 10 of this embodiment is in thermal contactwith a heat source 30 through a heat conductive piece 20. In otherwords, the heat conductive piece 20 is disposed between the heatdissipation device 10 and the heat source 30. Moreover, the heatconductive piece 20 is in thermal contact with the heat dissipationdevice 10 and the heat source 30. In this embodiment and otherembodiments, a layer of heat conductive adhesive 40 is further disposedbetween the heat conductive piece 20 and the heat source 30 for speedingup the transfer of the heat of the heat source 30 to the heatdissipation device 10. The heat conductive adhesive 40 is disposedbetween the heat conductive piece 20 and the heat source 30 in thisembodiment. However, it should not be construed as a limitation to thedisclosure. In other embodiments, heat conductive paste may be used inthe heat dissipation device.

In this embodiment, the heat dissipation device 10 comprises a pluralityof heat dissipation fins 100, a heat pipe 200 and a fan 300. Each of theheat dissipation fins 100 comprises a plate 110 and an air guiding body120. The plate 110 has an air inlet side 111 and an air outlet side 112disposed oppositely to each other as well as a side edge 113. The sideedge 113 is connected with the air inlet side 111 and the air outletside 112. The heat conductive piece 20 is disposed at the air outletside 112 in order that the heat dissipation fins 100 are in thermalcontact with the heat source 30 through the heat conductive piece 20.The plate 110 has a through hole 114. The heat pipe 200 is disposedinside the through hole 114 and is in thermal contact with the heatdissipation fin 100. The air guiding body 120 is protruded from theplate 110. An acute angle θ is formed between an extension side of theair guiding body 120 and a surface of the air outlet side 112. Thereby,the air guiding body 120 has the function for guiding air and the airguiding body 120 may also increase the heat dissipation area of the heatdissipation fins 100. Therefore, the heat dissipation effect of the heatdissipation fins 100 may be enhanced. Furthermore, the air guiding body120 may be in an arc shape. That is, the air guiding body 120 may have acorner radius.

Furthermore, each of the heat dissipation fins 100 in this embodimentcomprises the air guiding body 120. But it should not be construed as alimitation to the disclosure. In other embodiments, the heat dissipationfins 100 with and without the air guiding body 120 may be partially usedin the heat dissipation device 10. For example, the heat dissipationfins 100 without the air guiding body 120 and the heat dissipation fins100 with the air guiding body 120 are arranged alternatively.

The fan 300 is installed at the air inlet sides 111 of the heatdissipation fins 100. The fan 300 is used for forming an air current.The air current flows from the air inlet side 111 toward the air outletside 112 of the plate 110. The air guiding body 120 and the heat pipe200 are disposed in a flowing path of the air current. Therefore, theair guiding body 120 may guide the air current partially toward the heatpipe 200 and increase the amount of air flowing through the heat pipe200. Thereby, the heat dissipation effect of the heat dissipation device10 may be enhanced.

However, the heat dissipation effect of the heat dissipation device 10may not be enhanced by protruding the air guiding body 120 at anylocation of the plate 110. Practically, the air guiding body 120 isrequired to dispose at a specific location. Thereby, the heatdissipation effect of the heat dissipation device 10 may be effectivelyenhanced.

Specifically, the heat pipe 200 and the air guiding body 120 in thisembodiment are separated by a distance D. A connection line between acenter of the heat pipe 200 and the center of the air guiding body 120intersects with a flowing direction of the air current produced by thefan 300. Therefore, the air guiding body 120 may guide the air currentby the heat pipe 200 to the heat pipe 200. Furthermore, the heat pipe200 is disposed between the side edge 113 and the air guiding body 120.The air guiding body 120 has a first end 121 and a second end 122disposed oppositely to each other as well as an air receiving side 123.The first end 121 is closed to the air inlet side 111. The second end122 is closed to the air outlet side 112. A distance between the firstend 121 of the air guiding body 120 and the side edge 113 is larger thanthat between the second end 122 of the air guiding body 120 and the sideedge 113. Therefore, the acute angle θ is formed between the extensionside of the air guiding body 120 and the surface of the air outlet side112 as shown in FIG. 3A. Thereby, the air receiving side 123 of the airguiding body 120 faces the air inlet side 111 and the heat pipe 200. Thedistance mentioned herein between the heat pipe 200 and the air guidingbody 120 refers to the distance D between the center of the heat pipe200 and the first end 121 of the air guiding body 120. The distance D ispreferably to be between 5 mm and 30 mm. Additionally, the acute angle θmentioned herein is preferably to be between 15 and 75 degrees.

In this embodiment, the heat pipe 200 is disposed between the side edge113 and the air guiding body 120. However, it should not be construed asa limitation to the disclosure. In other embodiments, the air guidingbody 120 may be disposed between the heat pipe 200 and the side edge113. Specifically, in this embodiment, a distance between the first end121 of the air guiding body 120 and the side edge 113 is shorter thanthat between the second end 122 of the air guiding body 120 and the sideedge 113. Therefore, the acute angle θ is formed between the extensionside of the air guiding body 120 and the surface of the air outlet side112 as shown in FIG. 3B. Thereby, the air receiving side 123 of the airguiding body 120 faces the air inlet side 111 and the heat pipe 200.

Please refer to FIG. 4. FIG. 4 is an illustration of the air current ofthe heat dissipation device in FIG. 1. When the air current produced bythe fan 300 flows along an air entering direction a from the air inletside 111 of the plate 110 to the air outlet side 112 in contact with theheat source 30, the air current flows through the heat pipe 200 and theair guiding body 120. Specifically, the air current flows through theheat pipe 200 and the air guiding body 120 because the arrangeddirections of the heat pipe 200 and the air guiding body 120 are roughlyperpendicular to the air entering direction a. However, since the aircurrent is partially blocked by the air receiving side 123 of the airguiding body 120, the air current is guided to the heat pipe 200disposed by the air guiding body 120. Thereby, the amount of air flowingthrough the heat pipe 200 in a unit of time is increased substantially.Specifically, the temperature of the heat pipe 200 should be higher thanthat of the nearby heat dissipation fins 100. Thus, the disposition ofthe air guiding body 120 guides the air current near the heat pipe 200to intensively flow toward the heat pipe 200 with a higher temperature.Therefore, the heat pipe 200 may exchange heat with a large amount ofair current first which helps to remove the heat earlier. Thereby, theheat dissipation efficiency of the heat dissipation device 10 may beenhanced.

Please refer to List 1. List 1 shows results of tests under theconditions that the rotation speed of the fan 300 is at 4300 rpm, thevoltage of the fan is 12V, and the thermal power produced by the heatsource 30 is 150 watts. List 1 shows that the measured temperatures ofthe heat source 30 when the heat dissipation fins 100 are equipped withthe air guiding body 120 are lower than the measured temperatures of theheat source 30 when the heat dissipation fins 100 are not equipped withthe air guiding body 120. In this embodiment, the highest dissipationtemperature (namely, the most amount of the temperature dropped in thisembodiment) is measured when the acute angle θ between the extensionside of the air guiding body 120 and the surface of the air outlet side112 is 30 degrees.

List 1 shows the relationship between the acute angle θ (between theextension side of the air guiding body 120 and the surface of the airoutlet side 112) and the dissipated temperature (namely, temperaturedropped).

Temp- erature of Heat Ratio of Temperature of Source DissipatedIncreased Heat Source with Air Temperature Dissipation without AirGuiding (temperature Area Guiding Body Body dropped) θ = 30 degrees3.24% 88.1° C. 81.4° C. 6.7° C. θ = 45 degrees 4.84% 86.1° C. 82.5° C.3.6° C. θ = 30 degrees  1.7% 95.5° C. 90.6° C. 4.9° C. and corner radius= 20

According to the heat dissipation device and its heat dissipation finsdisclosed in the disclosure, by disposing an acute angle between theextension side of the air guiding body and the surface of the air outletside, the air receiving side of the air guiding body may face the airinlet side and the heat pipe. Therefore, when the air current flows fromthe air inlet side, the air current is guided by the air guiding bodyand will flow intensively toward the heat pipe. Thereby, the amount ofair flowing through the heat pipe in a unit of time is increased, andthus improves the heat dissipation efficiency of the heat dissipationdevice.

What is claimed is:
 1. A heat dissipation device configured for being inthermal contact with a heat source, the heat dissipation devicecomprising: a plurality of heat dissipation fins, each of some of theheat dissipation fins comprising a plate and an air guiding body, theplate having an air outlet side configured for being in thermal contactwith the heat source, the air guiding body being protruded from theplate, an acute angle being formed between an extension side of the airguiding body and a surface of the air outlet side; a heat pipepenetrating through the plates and the heat pipe being kept away fromthe air guiding body at a distance; and a fan installed at a side of theheat dissipation fins opposite to the air outlet side, the fan beingconfigured for forming an air current, and the air guiding body as wellas the heat pipe being disposed in a flowing path of the air current toguide the air current toward the heat pipe and to increase an amount ofair flowing through the heat pipe.
 2. The heat dissipation device asclaimed in claim 1, wherein the acute angle is between 15 and 75degrees.
 3. The heat dissipation device as claimed in claim 1, whereinthe plate has an air inlet side and a side edge, the air current flowsfrom the air inlet side toward the air outlet side, the side edge isconnected with the air inlet side and the air outlet side, the airguiding body has a first end and a second end disposed oppositely toeach other, the first end is close to the air inlet side, the second endis close to the air outlet side, the heat pipe is disposed between theside edge and the air guiding body, a distance between the first end ofthe air guiding body and the side edge is larger than that between thesecond end of the air guiding body and the side edge.
 4. The heatdissipation device as claimed in claim 1, wherein the plate has an airinlet side and a side edge, the air current flows from the air inletside toward the air outlet side, the side edge is connected with the airinlet side and the air outlet side, the air guiding body has a first endand a second end disposed oppositely to each other, the first end isclose to the air inlet side, the second end is close to the air outletside, the air guiding body is disposed between the side edge and theheat pipe, a distance between the first end of the air guiding body andthe side edge is shorter than that between the second end of the airguiding body and the side edge.
 5. The heat dissipation device asclaimed in claim 1, wherein a connection line between a center of theair guiding body and a center of the heat pipe intersects with a flowingdirection of the air current.
 6. A heat dissipation fin configured forinstalling a fan and a heat pipe, the fan producing an air current, theheat dissipation fin comprising: a plate having a through holeconfigured for accommodating the heat pipe, the heat pipe being inthermal contact with the plate, the plate having an air outlet side; andan air guiding body protruded from the plate, the air guiding body beingdisposed in a flowing path of the air current, and an acute angle beingdisposed between an extension side of the air guiding body as well as asurface of the air outlet side in order to guide the air current towardthe heat pipe and to increase an amount of air flowing through the heatpipe.
 7. The heat dissipation fin as claimed in claim 6, wherein theacute angle is between 15 and 75 degrees.
 8. The heat dissipation fin asclaimed in claim 6, wherein the plate has an air inlet side and a sideedge, the air current flows from the air inlet side toward the airoutlet side, the side edge is connected with the air inlet side and theair outlet side, the air guiding body has a first end and a second enddisposed oppositely to each other, the first end is close to the airinlet side, the second end is close to the air outlet side, the heatpipe is disposed between the side edge and the air guiding body, adistance between the first end of the air guiding body and the side edgeis longer than that between the second end of the air guiding body andthe side edge.
 9. The heat dissipation fin as claimed in claim 6,wherein the plate has an air inlet side and a side edge, the air currentflows from the air inlet side toward the air outlet side, the side edgeis connected with the air inlet side and the air outlet side, the airguiding body has a first end and a second end disposed oppositely toeach other, the first end is close to the air inlet side, the second endis close to the air outlet side, the air guiding body is disposedbetween the side edge and the heat pipe, a distance between the firstend of the air guiding body and the side edge is shorter than thatbetween the second end of the air guiding body and the side edge.